Know and understand functionality including Internet Service Provider (ISP), structure of a web address, Uniform Resource Locator (URL), hyperlink, web browser

Published by Patrick Mutisya · 14 days ago

ICT 0417 – Communication Notes

10 Communication

Objective

Know and understand the functionality of Internet Service Providers (ISPs), the structure of a web address, Uniform Resource Locators (URL), hyperlinks and web browsers.

Internet Service Provider (ISP)

An ISP is a company that provides individuals and organisations with access to the Internet and related services.

  • Types of ISP: dial‑up, broadband (DSL, cable, fibre), wireless, satellite.

  • Key functions:

    • Provide a connection to the Internet.

    • Assign IP addresses.

    • Offer additional services such as email, web hosting, and security.

  • Typical charges: monthly subscription, installation fee, data allowance.

Structure of a Web Address

A web address, or URL, is made up of several distinct parts that tell a browser how to locate a resource.

ComponentExamplePurpose
Protocolhttps://Specifies the communication method (e.g., HTTP, HTTPS, FTP).
Subdomainwww.Optional prefix that can identify a specific service or server.
Domain nameexampleHuman‑readable name registered with a domain registrar.
Top‑level domain (TLD).comIndicates the category or country of the domain.
Port (optional):443Specifies a particular network port; default ports are assumed if omitted.
Path/folder/page.htmlPoints to a specific file or resource on the server.
Query string (optional)?id=25&type=studentPasses parameters to the server‑side script.
Fragment (optional)#section2Directs the browser to a specific part of the page.

Uniform Resource Locator (URL)

The URL is the complete address that a web browser uses to retrieve a resource.

  1. Start with the protocol (e.g., http:// or https://).

  2. Follow with the domain name and optional subdomain.

  3. Add any required port number.

  4. Include the path to the file or directory.

  5. Append a query string if data needs to be sent to the server.

  6. Finish with a fragment identifier if you want to jump to a section within the page.

Hyperlink

A hyperlink (or link) connects one web page to another, or to a different part of the same page.

  • Created with the HTML <a> element.

  • Syntax: <a href="URL">Link text</a>.

  • Attributes:

    • href – the destination URL.

    • target – where to open the link (e.g., _blank for a new tab).

    • title – optional tooltip text.

  • Types of links:

    • External – points to a different website.

    • Internal – points to another page within the same site.

    • Anchor – jumps to a specific section using a fragment identifier.

    • Download – links to a file for download.

Web Browser

A web browser is software that interprets HTML, CSS, JavaScript and other web technologies to display web pages.

FunctionDescription
Render HTML/CSSTransforms markup into a visual layout.
Execute JavaScriptEnables interactive features and dynamic content.
Manage sessionsStores cookies, cache and browsing history.
SecurityImplements HTTPS, warns about unsafe sites, and isolates content (sandbox).
Navigation controlsAddress bar, back/forward buttons, refresh, bookmarks.

Suggested diagram: Flow of a web request – ISP → DNS lookup → Server → Browser rendering.

Summary Checklist

  • Identify the role of an ISP in providing Internet access.

  • Break down a URL into protocol, domain, TLD, path, query string and fragment.

  • Write a basic hyperlink using the <a> tag.

  • Explain how a web browser retrieves and displays a web page.